It's a sad state of affairs in major Polish cities. Out of the 4 major tech hubs: Warsaw, Krakow, Wroclaw, 3-city (Gdansk/Sopot/Gdynia which form one long city) air is terrible in all with the exception of 3-city. Even there it's not so rosy (depends on the area, some are very clean, some not so much but air pollution stations are too sparse to show it). I moved out because of it and I wouldn't advise anyone to live in Poland (outside 3-city) if they have other options. It's not worth it to risk your health.

The situation is terrible for many reasons but major 2 are ancient coal/junk heating (people won't upgrade to eco-friendly heating because most of them are dirty poor and their main problem is to find a cheaper coal substitute for next winter) and Germans flooding us with used diesel cars with particulate filters long not working (or removed). There is a lot of talk about CO2 but this is long term danger while used diesel cars are poisoning us right now at massive scale.